trigger.module

<?php


/**
 * @file
 * Enables functions to be stored and executed at a later time.
 */

/**
 * Implements hook_help().
 */
function trigger_help($path, $arg) {
    // Generate help text for admin/structure/trigger/(module) tabs.
    $matches = array();
    if (preg_match('|^admin/structure/trigger/(.*)$|', $path, $matches)) {
        $explanation = '<p>' . t('Triggers are events on your site, such as new content being added or a user logging in. The Trigger module associates these triggers with actions (functional tasks), such as unpublishing content containing certain keywords or e-mailing an administrator. The <a href="@url">Actions settings page</a> contains a list of existing actions and provides the ability to create and configure advanced actions (actions requiring configuration, such as an e-mail address or a list of banned words).', array(
            '@url' => url('admin/config/system/actions'),
        )) . '</p>';
        $module = $matches[1];
        $trigger_info = _trigger_tab_information();
        if (!empty($trigger_info[$module])) {
            $explanation .= '<p>' . t('There is a tab on this page for each module that defines triggers. On this tab you can assign actions to run when triggers from the <a href="@module-help">@module-name module</a> happen.', array(
                '@module-help' => url('admin/help/' . $module),
                '@module-name' => $trigger_info[$module],
            )) . '</p>';
        }
        return $explanation;
    }
    if ($path == 'admin/help#trigger') {
        $output = '';
        $output .= '<h3>' . t('About') . '</h3>';
        $output .= '<p>' . t('The Trigger module provides the ability to cause <em>actions</em> to run when certain <em>triggers</em> take place on your site. Triggers are events, such as new content being added to your site or a user logging in, and actions are tasks, such as unpublishing content or e-mailing an administrator. For more information, see the online handbook entry for <a href="@trigger">Trigger module</a>.', array(
            '@trigger' => 'http://drupal.org/documentation/modules/trigger/',
        )) . '</p>';
        $output .= '<h3>' . t('Uses') . '</h3>';
        $output .= '<dl>';
        $output .= '<dt>' . t('Configuring triggers and actions') . '</dt>';
        $output .= '<dd>' . t('The combination of actions and triggers can perform many useful tasks, such as e-mailing an administrator if a user account is deleted, or automatically unpublishing comments that contain certain words. To set up a trigger/action combination, first visit the <a href="@actions-page">Actions configuration page</a>, where you can either verify that the action you want is already listed, or create a new <em>advanced</em> action. You will need to set up an advanced action if there are configuration options in your trigger/action combination, such as specifying an e-mail address or a list of banned words. After configuring or verifying your action, visit the <a href="@triggers-page">Triggers configuration page</a> and choose the appropriate tab (Comment, Taxonomy, etc.), where you can assign the action to run when the trigger event occurs.', array(
            '@triggers-page' => url('admin/structure/trigger'),
            '@actions-page' => url('admin/config/system/actions'),
        )) . '</dd>';
        $output .= '</dl>';
        return $output;
    }
}

/**
 * Implements hook_menu().
 */
function trigger_menu() {
    $items['admin/structure/trigger'] = array(
        'title' => 'Triggers',
        'description' => 'Configure when to execute actions.',
        'page callback' => 'trigger_assign',
        'access arguments' => array(
            'administer actions',
        ),
        'file' => 'trigger.admin.inc',
    );
    $trigger_info = _trigger_tab_information();
    foreach ($trigger_info as $module => $module_name) {
        $items["admin/structure/trigger/{$module}"] = array(
            'title' => $module_name,
            'page callback' => 'trigger_assign',
            'page arguments' => array(
                $module,
            ),
            'access arguments' => array(
                'administer actions',
            ),
            'type' => MENU_LOCAL_TASK,
            'file' => 'trigger.admin.inc',
        );
    }
    $items['admin/structure/trigger/unassign'] = array(
        'title' => 'Unassign',
        'description' => 'Unassign an action from a trigger.',
        'page callback' => 'drupal_get_form',
        'page arguments' => array(
            'trigger_unassign',
        ),
        // Only accessible if there are any actions that can be unassigned.
'access callback' => 'trigger_menu_unassign_access',
        // Only output in the breadcrumb, not in menu trees.
'type' => MENU_VISIBLE_IN_BREADCRUMB,
        'file' => 'trigger.admin.inc',
    );
    return $items;
}

/**
 * Access callback: Determines if triggers can be unassigned.
 *
 * @return bool
 *   TRUE if there are triggers that the user can unassign, FALSE otherwise.
 *
 * @see trigger_menu()
 */
function trigger_menu_unassign_access() {
    if (!user_access('administer actions')) {
        return FALSE;
    }
    $count = db_select('trigger_assignments')->countQuery()
        ->execute()
        ->fetchField();
    return $count > 0;
}

/**
 * Implements hook_trigger_info().
 *
 * Defines all the triggers that this module implements triggers for.
 */
function trigger_trigger_info() {
    return array(
        'node' => array(
            'node_presave' => array(
                'label' => t('When either saving new content or updating existing content'),
            ),
            'node_insert' => array(
                'label' => t('After saving new content'),
            ),
            'node_update' => array(
                'label' => t('After saving updated content'),
            ),
            'node_delete' => array(
                'label' => t('After deleting content'),
            ),
            'node_view' => array(
                'label' => t('When content is viewed by an authenticated user'),
            ),
        ),
        'comment' => array(
            'comment_presave' => array(
                'label' => t('When either saving a new comment or updating an existing comment'),
            ),
            'comment_insert' => array(
                'label' => t('After saving a new comment'),
            ),
            'comment_update' => array(
                'label' => t('After saving an updated comment'),
            ),
            'comment_delete' => array(
                'label' => t('After deleting a comment'),
            ),
            'comment_view' => array(
                'label' => t('When a comment is being viewed by an authenticated user'),
            ),
        ),
        'taxonomy' => array(
            'taxonomy_term_insert' => array(
                'label' => t('After saving a new term to the database'),
            ),
            'taxonomy_term_update' => array(
                'label' => t('After saving an updated term to the database'),
            ),
            'taxonomy_term_delete' => array(
                'label' => t('After deleting a term'),
            ),
        ),
        'system' => array(
            'cron' => array(
                'label' => t('When cron runs'),
            ),
        ),
        'user' => array(
            'user_insert' => array(
                'label' => t('After creating a new user account'),
            ),
            'user_update' => array(
                'label' => t('After updating a user account'),
            ),
            'user_delete' => array(
                'label' => t('After a user has been deleted'),
            ),
            'user_login' => array(
                'label' => t('After a user has logged in'),
            ),
            'user_logout' => array(
                'label' => t('After a user has logged out'),
            ),
            'user_view' => array(
                'label' => t("When a user's profile is being viewed"),
            ),
        ),
    );
}

/**
 * Gets the action IDs of actions to be executed for a hook.
 *
 * @param $hook
 *   The name of the hook being fired.
 *
 * @return
 *   An array whose keys are action IDs that the user has associated with
 *   this trigger, and whose values are arrays containing the action type and
 *   label.
 */
function trigger_get_assigned_actions($hook) {
    $actions =& drupal_static(__FUNCTION__, array());
    if (!isset($actions[$hook])) {
        $actions[$hook] = db_query("SELECT ta.aid, a.type, a.label FROM {trigger_assignments} ta LEFT JOIN {actions} a ON ta.aid = a.aid WHERE ta.hook = :hook ORDER BY ta.weight", array(
            ':hook' => $hook,
        ))->fetchAllAssoc('aid', PDO::FETCH_ASSOC);
    }
    return $actions[$hook];
}

/**
 * Implements hook_theme().
 */
function trigger_theme() {
    return array(
        'trigger_display' => array(
            'render element' => 'element',
            'file' => 'trigger.admin.inc',
        ),
    );
}

/**
 * Implements hook_forms().
 *
 * We re-use code by using the same assignment form definition for each hook.
 */
function trigger_forms() {
    $trigger_info = _trigger_get_all_info();
    $forms = array();
    foreach ($trigger_info as $module => $hooks) {
        foreach ($hooks as $hook => $description) {
            $forms['trigger_' . $hook . '_assign_form'] = array(
                'callback' => 'trigger_assign_form',
            );
        }
    }
    return $forms;
}

/**
 * Loads associated objects for node triggers.
 *
 * When an action is called in a context that does not match its type, the
 * object that the action expects must be retrieved. For example, when an action
 * that works on users is called during a node hook implementation, the user
 * object is not available since the node hook call doesn't pass it. So here we
 * load the object the action expects.
 *
 * @param $type
 *   The type of action that is about to be called.
 * @param $node
 *   The node that was passed via the node hook.
 *
 * @return
 *   The object expected by the action that is about to be called.
 */
function _trigger_normalize_node_context($type, $node) {
    // Note that comment-type actions are not supported in node contexts,
    // because we wouldn't know which comment to choose.
    switch ($type) {
        // An action that works on users is being called in a node context.
        // Load the user object of the node's author.
        case 'user':
            return user_load($node->uid);
    }
}

/**
 * Calls action functions for node triggers.
 *
 * @param $node
 *   Node object.
 * @param $hook
 *   Hook to trigger.
 * @param $a3
 *   Additional argument to action function.
 * @param $a4
 *   Additional argument to action function.
 */
function _trigger_node($node, $hook, $a3 = NULL, $a4 = NULL) {
    // Keep objects for reuse so that changes actions make to objects can persist.
    static $objects;
    // Prevent recursion by tracking which operations have already been called.
    static $recursion;
    $aids = trigger_get_assigned_actions($hook);
    if (!$aids) {
        return;
    }
    if (isset($recursion[$hook])) {
        return;
    }
    $recursion[$hook] = TRUE;
    $context = array(
        'group' => 'node',
        'hook' => $hook,
    );
    // We need to get the expected object if the action's type is not 'node'.
    // We keep the object in $objects so we can reuse it if we have multiple actions
    // that make changes to an object.
    foreach ($aids as $aid => $info) {
        $type = $info['type'];
        if ($type != 'node') {
            if (!isset($objects[$type])) {
                $objects[$type] = _trigger_normalize_node_context($type, $node);
            }
            // Since we know about the node, we pass that info along to the action.
            $context['node'] = $node;
            $result = actions_do($aid, $objects[$type], $context, $a3, $a4);
        }
        else {
            actions_do($aid, $node, $context, $a3, $a4);
        }
    }
    unset($recursion[$hook]);
}

/**
 * Implements hook_node_view().
 */
function trigger_node_view($node, $view_mode) {
    _trigger_node($node, 'node_view', $view_mode);
}

/**
 * Implements hook_node_update().
 */
function trigger_node_update($node) {
    _trigger_node($node, 'node_update');
}

/**
 * Implements hook_node_presave().
 */
function trigger_node_presave($node) {
    _trigger_node($node, 'node_presave');
}

/**
 * Implements hook_node_insert().
 */
function trigger_node_insert($node) {
    _trigger_node($node, 'node_insert');
}

/**
 * Implements hook_node_delete().
 */
function trigger_node_delete($node) {
    _trigger_node($node, 'node_delete');
}

/**
 * Loads associated objects for comment triggers.
 *
 * When an action is called in a context that does not match its type, the
 * object that the action expects must be retrieved. For example, when an action
 * that works on nodes is called during the comment hook, the node object is not
 * available since the comment hook doesn't pass it. So here we load the object
 * the action expects.
 *
 * @param $type
 *   The type of action that is about to be called.
 * @param $comment
 *   The comment that was passed via the comment hook.
 *
 * @return
 *   The object expected by the action that is about to be called.
 */
function _trigger_normalize_comment_context($type, $comment) {
    switch ($type) {
        // An action that works with nodes is being called in a comment context.
        case 'node':
            return node_load(is_array($comment) ? $comment['nid'] : $comment->nid);
        // An action that works on users is being called in a comment context.
        case 'user':
            return user_load(is_array($comment) ? $comment['uid'] : $comment->uid);
    }
}

/**
 * Implements hook_comment_presave().
 */
function trigger_comment_presave($comment) {
    _trigger_comment($comment, 'comment_presave');
}

/**
 * Implements hook_comment_insert().
 */
function trigger_comment_insert($comment) {
    _trigger_comment($comment, 'comment_insert');
}

/**
 * Implements hook_comment_update().
 */
function trigger_comment_update($comment) {
    _trigger_comment($comment, 'comment_update');
}

/**
 * Implements hook_comment_delete().
 */
function trigger_comment_delete($comment) {
    _trigger_comment($comment, 'comment_delete');
}

/**
 * Implements hook_comment_view().
 */
function trigger_comment_view($comment) {
    _trigger_comment($comment, 'comment_view');
}

/**
 * Calls action functions for comment triggers.
 *
 * @param $a1
 *   Comment object or array of form values.
 * @param $hook
 *   Hook to trigger.
 */
function _trigger_comment($a1, $hook) {
    // Keep objects for reuse so that changes actions make to objects can persist.
    static $objects;
    $aids = trigger_get_assigned_actions($hook);
    $context = array(
        'group' => 'comment',
        'hook' => $hook,
    );
    // We need to get the expected object if the action's type is not 'comment'.
    // We keep the object in $objects so we can reuse it if we have multiple
    // actions that make changes to an object.
    foreach ($aids as $aid => $info) {
        $type = $info['type'];
        if ($type != 'comment') {
            if (!isset($objects[$type])) {
                $objects[$type] = _trigger_normalize_comment_context($type, $a1);
            }
            // Since we know about the comment, we pass it along to the action
            // in case it wants to peek at it.
            $context['comment'] = (object) $a1;
            actions_do($aid, $objects[$type], $context);
        }
        else {
            actions_do($aid, $a1, $context);
        }
    }
}

/**
 * Implements hook_cron().
 */
function trigger_cron() {
    $aids = trigger_get_assigned_actions('cron');
    $context = array(
        'group' => 'cron',
        'hook' => 'cron',
    );
    // Cron does not act on any specific object.
    $object = NULL;
    actions_do(array_keys($aids), $object, $context);
}

/**
 * Loads associated objects for user triggers.
 *
 * When an action is called in a context that does not match its type, the
 * object that the action expects must be retrieved. For example, when an action
 * that works on nodes is called during the user hook, the node object is not
 * available since the user hook doesn't pass it. So here we load the object the
 * action expects.
 *
 * @param $type
 *   The type of action that is about to be called.
 * @param $account
 *   The account object that was passed via the user hook.
 *
 * @return
 *   The object expected by the action that is about to be called.
 */
function _trigger_normalize_user_context($type, $account) {
    // Note that comment-type actions are not supported in user contexts,
    // because we wouldn't know which comment to choose.
    switch ($type) {
        // An action that works with nodes is being called in a user context.
        // If a single node is being viewed, return the node.
        case 'node':
            // If we are viewing an individual node, return the node.
            if (arg(0) == 'node' && is_numeric(arg(1)) && arg(2) == NULL) {
                return node_load(array(
                    'nid' => arg(1),
                ));
            }
            break;
    }
}

/**
 * Implements hook_user_login().
 */
function trigger_user_login(&$edit, $account, $category) {
    _trigger_user('user_login', $edit, $account, $category);
}

/**
 * Implements hook_user_logout().
 */
function trigger_user_logout($account) {
    $edit = array();
    _trigger_user('user_logout', $edit, $account);
}

/**
 * Implements hook_user_insert().
 */
function trigger_user_insert(&$edit, $account, $category) {
    _trigger_user('user_insert', $edit, $account, $category);
}

/**
 * Implements hook_user_update().
 */
function trigger_user_update(&$edit, $account, $category) {
    _trigger_user('user_update', $edit, $account, $category);
}

/**
 * Implements hook_user_cancel().
 */
function trigger_user_cancel($edit, $account, $method) {
    switch ($method) {
        case 'user_cancel_reassign':
            _trigger_user('user_delete', $edit, $account, $method);
            break;
    }
}

/**
 * Implements hook_user_delete().
 */
function trigger_user_delete($account) {
    $edit = array();
    _trigger_user('user_delete', $edit, $account, NULL);
}

/**
 * Implements hook_user_view().
 */
function trigger_user_view($account) {
    $edit = NULL;
    _trigger_user('user_view', $edit, $account, NULL);
}

/**
 * Calls action functions for user triggers.
 *
 * @param $hook
 *   The hook that called this function.
 * @param $edit
 *   Edit variable passed in to the hook or empty array if not needed.
 * @param $account
 *   Account variable passed in to the hook.
 * @param $method
 *   Method variable passed in to the hook or NULL if not needed.
 */
function _trigger_user($hook, &$edit, $account, $category = NULL) {
    // Keep objects for reuse so that changes actions make to objects can persist.
    static $objects;
    $aids = trigger_get_assigned_actions($hook);
    $context = array(
        'group' => 'user',
        'hook' => $hook,
        'form_values' => &$edit,
    );
    foreach ($aids as $aid => $info) {
        $type = $info['type'];
        if ($type != 'user') {
            if (!isset($objects[$type])) {
                $objects[$type] = _trigger_normalize_user_context($type, $account);
            }
            $context['user'] = $account;
            actions_do($aid, $objects[$type], $context);
        }
        else {
            actions_do($aid, $account, $context, $category);
        }
    }
}

/**
 * Calls action functions for taxonomy triggers.
 *
 * @param $hook
 *   Hook to trigger actions for taxonomy_term_insert(),
 *   taxonomy_term_update(), and taxonomy_term_delete().
 * @param $array
 *   Item on which operation is being performed, either a term or
 *   form values.
 */
function _trigger_taxonomy($hook, $array) {
    $aids = trigger_get_assigned_actions($hook);
    $context = array(
        'group' => 'taxonomy',
        'hook' => $hook,
    );
    actions_do(array_keys($aids), (object) $array, $context);
}

/**
 * Implements hook_taxonomy_term_insert().
 */
function trigger_taxonomy_term_insert($term) {
    _trigger_taxonomy('taxonomy_term_insert', (array) $term);
}

/**
 * Implements hook_taxonomy_term_update().
 */
function trigger_taxonomy_term_update($term) {
    _trigger_taxonomy('taxonomy_term_update', (array) $term);
}

/**
 * Implements hook_taxonomy_term_delete().
 */
function trigger_taxonomy_term_delete($term) {
    _trigger_taxonomy('taxonomy_term_delete', (array) $term);
}

/**
 * Implements hook_actions_delete().
 *
 * Removes all trigger entries for the given action, when an action is deleted.
 */
function trigger_actions_delete($aid) {
    db_delete('trigger_assignments')->condition('aid', $aid)
        ->execute();
    drupal_static_reset('trigger_get_assigned_actions');
}

/**
 * Retrieves and caches information from hook_trigger_info() implementations.
 *
 * @return
 *   Array of all triggers.
 */
function _trigger_get_all_info() {
    $triggers =& drupal_static(__FUNCTION__);
    if (!isset($triggers)) {
        $triggers = module_invoke_all('trigger_info');
        drupal_alter('trigger_info', $triggers);
    }
    return $triggers;
}

/**
 * Gathers information about tabs on the triggers administration screen.
 *
 * @return
 *   Array of modules that have triggers, with the keys being the
 *   machine-readable name of the module, and the values being the
 *   human-readable name of the module.
 */
function _trigger_tab_information() {
    // Gather information about all triggers and modules.
    $trigger_info = _trigger_get_all_info();
    $modules = system_get_info('module');
    $modules = array_intersect_key($modules, $trigger_info);
    $return_info = array();
    foreach ($modules as $name => $info) {
        $return_info[$name] = $info['name'];
    }
    return $return_info;
}